(CBS News) In the first debate between the Massachusetts Senate candidates, challenger Elizabeth Warren attempted to paint incumbent Sen. Scott Brown as a corporate shill in lock-step with his Republican colleagues concerned about protecting the wealthy, while the senator framed Warren as liberal intent on raising taxes.

"She's obsessed with raising taxes," Brown said during Thursday night's debate in Boston, adding that "there's a spending problem in Washington, D.C." and that Warren would continue to fuel the fire.

"She would have raised taxes on you," he said, pointing to the camera, in defense of voting against a bill in the Senate that would have reduced the interest rates of student loans by raising taxes on high-income earners. "I am on the taxpayers' side."

Repeating the position of national Democrats, Warren said Washington needs to take "a balanced approach" to reducing the deficit by cutting spending and raising revenue. She also said that Brown has "rigged the playing field" by voting to extend subsidies for oil companies.

Brown painted himself as a moderate Republican who has worked on issues important to the late Sen. Ted Kennedy, including preventing wind farms off the coast of Nantucket, and has voted with Democrats. He said numerous times that he is the "second most bipartisan senator in the Senate."

He used the line when Warren, a Harvard professor, said control of the Senate could hang on the Massachusetts Senate race. She said Sen. James Inhofe, R-Okla., who believes global warming is a hoax, could lead the committee that overseas environmental policy if Republicans take control of the Senate.

In the first debate of one of the most closely watched Senate races in the country, which has been tight for many months, both Warren and Brown lobbed attacks while playing defense much of the one-hour face-off.

"Sen. Brown can say all he wants but he has voted," Warren said, continuously pointing to votes Brown has taken in the Senate.

"Women need someone they can depend on, not some of the time but all of the time," she added, charging Brown with voting against a bill that would require women make equal amounts of money as their male counterparts and co-sponsoring a measure, known as the Blunt amendment after the Missouri senator, that would have gutted President Obama's mandate that employers provide free contraception health coverage.

"You should stop scarring women," Brown shot back, adding that both he and Warren are both pro-choice and that he's been "fighting for women's rights" since he was a child as his mother was abused by his step-father.

The debate debate opened with both candidates on the attack. Brown said Warren should release her personal files from Harvard, where she listed her ethnicity as Native American, to prove that she did not receive an advantage for being a minority.

"The only way to get this straight is for you to release your personnel records," he said, saying it "speaks volumes" that she has not done so.

Brown also said the cost of higher education has skyrocketed, in part, because of administrative costs, pointing to Warren's several-hundred thousand dollar salary there "in addition the housing and other perks," he said. "No wonder the costs are high."

Meantime, Warren said Brown would "hold the other 98 percent of families hostage if there is not tax breaks for the top."

Brown did not utter the words of the Republican presidential candidate Mitt Romney, the former governor of the state, who has no chance of winning the liberal state in November.

Warren invoked President Obama's name, however, when the debate turned to foreign policy, an issue in which polls show voters approve of the president's handling.

"I support President Obama," she said, arguing that the president has "done a first-rate job" in using sanctions and diplomacy and leaving all options of the table to prevent Iran from obtaining a nuclear weapon. "I'm still working to have President Obama be the commander-in-chief, not Mitt Romney."

Emphasizing his independence from the Republican Party, Brown praised Secretary of State Hillary Clinton as "a bright star in that administration," but said the president started strong but has gotten weak on Iran, adding that "we cannot have a nuanced approach."